The Arizona sentinel., 1887-01-08
THE CARE OF THE EYES.
A Few Simple Rules Which All
 Should Follow.
I. THE HYGIENE OF THE EYES.

I. THE HYGIENE OF THE EYES.
 What I have to say on this subject may be reduced to half a dozen rules none of them hard to follow, unless it be the last of them but one.
 1. My first rule is, in reading, have light enough for easy vision. How much light is enough? How much is too much? These are questions for the individual. No two persons require the same brightness upon the page. Some eyes are timid of light, and can stand but little of it, while yet they may be depended on for a good many hours work in the day and for good many years service. Strong eyes, those that will bear the glare, are not infrequently those that run the greatest risk of abuse; just as the persons who have excellent digestions or great oth- letic powers are constantly tempted to over-exercise them and to break them down, while weaker persons who take care of themselves will Outlast the strong. Comfort in reading is the main criterion.
 The main temptation is to strain the eyes in reading when the light is in- sufficient. This must be strenuously resisted if the retina is to be kept in good working order Less light is re- quired in writing than in reading, be- cause the trained movements of the in considerable degree independent of blind shows how easily they may l,A But it is precisely the experience of the blind that we wish, in our own per sons. to avoid. Let us, therefore, allow ourselves quite enough light in every case; more in reading, less, if need be in writing; but enough in each and every case. In mountain camp, by a tallow candle, you might well enough write letter without straining your eyesight; while it might fatigue your eyes to read the same letter after you had written it.
 ?. Either in reading or writing, the direction of the light is important. It will not do to read against the light, i. e., with the light in your face, be- cause then the direct glare contends upon the retina with the fainter image of the object. The light should fall from behind; and there is a choice as 10 which side. At least in writing, it should come from behind the left shOul- der, because then the shadow of the hand falls away from the pen instead of upon it. Every writer does not know this, or at least does not bear it in mind. knew a literary man who had written prose and poetry all his life, and who was in the habit, until l showed him his mistake, of letting the light fall from his right shoulder-in this case the wrong shoulder-upon his paper; he had sat in his own light for thirty years. It must have affected the quality of his poetry. In reading, un- less your eyes are protected by shade and shade is an excellent thing let the daylight or the candle-light fall npon your page from behind, whenever youca conveniently manageit, by turn ing your chair or by choosing the posi- ton of the lamp. Nothingis more try ing than reading against the glare, un- less it be reading by the twilight,- great temptation to some enthusiastic students.
 3. When the sunlight fails, do not de- pend upon the twilight, and do not combine gas-light or lamp-light with the twilight. Unmixed light is always the best, whether it be solar, or electric, or from any other artificial source. The improved electric lights will prove great boon to students, especially to summer students, not only on account of their pure and steady illumination, but because they neither heat the air nor consume it. It is hard to see what farther improvement-excep in the very desirable matter of cheapness-is likely to be required in the better incan- descent lights that are now coming into use. The arc lights, with their wild f1ickering brilliancy, are another mat ter.
 f. Every one knows, but every one does not always bear in mind, that the page one reads should be held steadily before the eyes in order to avoid undue strain on the muscles of accommoda- ton. Not only this, but it is worth while to form the habit of holding the page so that the top of the page and the bottom shall be eqfidistant from the eye. This may seem a very minute precaution, and such it is; yet nothing is trivial which tends to the better preservation of the delicate functions of the organ; and the habit is onewhich is easily learned. Reading in the cars is a thing which one would hardly un- dertake to defend on theory; yet it is a practice which is likely to increase rath- CT than to diminish, especially with the increasing smoothness of railway travel. The things to bear in mind are that the book or paper should be held as steadily as possible under the circum- stances; and that in the railway car there is double reason for taking time to think upon what one reads.